Question

 var word_count = rdd.flatMap(lines=>lines.split(",").map(words=>(words,1)).reduceByKey(_+_).collect
word_count:Array[(String,Int)] = Array((Ankita,1),(shelly,1),(A,2),(B,1))

//现在编写以下查询结果为空字符串，但我想提取（A，2）和（B，1）。

var filtered = word_count.filter(values=>(values=="A") || (values=="B")).collect 
filtered:Array[(String,Int)] = Array()

Answer 1

应该是：

word_count.filter(x => (x._1 == "A") || (x._1 == "B"))

或

word_count.filter(x => Seq("A", "B").contains(x._1))

您的代码将Tuple2与String进行比较，给出了虚假的表达：

scala> ("A", 1) == "A"
<console>:24: warning: comparing values of types (String, Int) and String using `==' will always yield false
       ("A", 1) == "A"
            ^
res0: Boolean = false

SCALA：用例从Array中提取特定值

1 个答案: